What are two essential characteristics of a good experiment?

1) one variable is tested2) a control is used

The correct answer is a

It developed as a reaction to the impact of european colonialism in africa on peoples of african descent. in the  mid-20th century, activists in africa adopted pan-africanism as a rallying cry for independence from colonial rule. some african pan-africanists sought to unite the continent as one independenthope it was useful